This invention relates to the art of pressure molding moldable material to form a shaped article and specifically relates to pressure molding a patty of a moldable food material such as ground raw beef and other shapable and plastic food materials by compressing the moldable material into a mold opening of a movable mold to give it a desired shape.
The invention particularly pertains to an automatically operable valved vent structure in which air and such fluids as are within the mold opening are ejected from the opening by the pressure of the advancing pressurized charge of material and with a rigid valve member such as a metal valve member being automatically moved to vent closing position when the mold opening is filled with the moldable material. This movement of the valve member is caused by the pressure of the advancing pressurized material. The valve is automatically returned to open position when the mold is moved to a second position such as one in which the molded article is removed.